1. Field of the Invention
This invention relates to novel halo-4-alkenoic acids and to their prepationon. More particularly, this invention relates to novel halo-4-alkenoic acids which are useful intermediates for the synthesis of insecticides and miticides and methods of their preparation.
2. Description of the Prior Art
Certain related halo-4-alkenoic acids reported in the literature are summarized in Table I below:
TABLE I ______________________________________ Known Halo-4-Alkenoic Acids having the following structural formula I: ##STR1## I Chem. Abstracts R.sub.1 R.sub.2 R.sub.3 R.sub.4 R.sub.5 R.sub.6 Reference ______________________________________ H H Br H H CH.sub.2 CH.sub.3 55:11293d H H Br H H n-C.sub.3 H.sub.7 55:11293d H H Br H H i-C.sub.3 H.sub.7 55:11293d H H Br H H n-C.sub.4 H.sub.9 54:1286b H H Br H H i-C.sub.4 H.sub.9 55:11293d H H Cl H H CH.sub.3 55:20946f H H Cl H H CH.sub.2 CH.sub.3 55:20946f H H Cl H H n-C.sub.3 H.sub.7 55:20946f H H Cl H H i-C.sub.5 H.sub.11 55-20946f Cl H H H H CH.sub.3 55:20951a Cl H H H H CH.sub.2 CH.sub.3 55:20951a Cl H H H H n-C.sub.3 H.sub.7 55:20951b Cl H H H H n-C.sub.4 H.sub.9 55:20951a Cl H H H H i-C.sub.4 H.sub.9 55:20951b Cl H H H H i-C.sub.5 H.sub.11 55:20951b Cl Cl H H H CH.sub.2 CH.sub.3 70:3222c Cl Cl H H H n-C.sub.3 H.sub.7 66:54994h Cl Cl H H H n-C.sub.4 H.sub.9 70:3222e Cl Cl H H H i-C.sub.5 H.sub.11 70:3222e CH.sub.3 Cl H H H CH.sub.3 80:81951n; 53:21649c CH.sub.3 Cl H H H CH.sub.2 CH.sub.3 80:81951n CH.sub.3 Cl H H H n-C.sub.3 H.sub.7 80:81951n; 54:283i CH.sub.3 Cl H H H i-C.sub.3 H.sub.7 54:1400g CH.sub.3 Cl H H H n-C.sub.4 H.sub.9 40:3397 CH.sub.3 Cl H H H i-C.sub.4 H.sub.9 80:81951n CH.sub.3 Cl CH.sub.3 H H CH.sub.2 CH.sub.3 71:70046j CH.sub.3 Cl CH.sub.3 H H i-C.sub.4 H.sub.9 71:70046j CH.sub.3 Cl CH.sub.3 H H i-C.sub.5 H.sub.11 71:70046j CH.sub.3 Cl CH.sub.3 H H n-C.sub.5 H.sub.11 71:70046j CH.sub.3 Cl CH.sub.3 H H n-C.sub.3 H.sub.7 71:70046j ______________________________________
All of the acids shown in Table I above were prepared by the malonic ester synthesis, a typical example of which is shown below (as described in M. T. Dangyan and G. M. Shakhnazaryan, Zvest., Akad. Nauk Armyan, S.S.R. Khim. Nauki 13, No. 4, 259-62 (1960)). ##STR2##
Belgium Pat. No. 860,687 discloses phenoxybenzyl haloalkenoate esters which are useful as insecticides and acaricides and have the following structural formula II: ##STR3## wherein: X is halogen, Y is halogen or CH.sub.3, Z is CN or ethynyl, and R.sub.1 is H or CH.sub.3. The esters of Belgium Pat. No. 860,687 are prepared using acids exemplified by the structural formula: ##STR4## wherein X, Y and R.sub.1 are as defined in formula II hereinabove.
Belgium Pat. No. 862,499 discloses a group of pyrethroidal esters which are characterized by the so-called "pydrinalcohol" and a class of olefinic esters. The pesticidal phenoxy benzyl pentene carboxylates are prepared by esterifying a phenoxy benzyl alcohol with pentene carboxylic acid. According to the disclosure of Belgium Pat. No. 862,499, the pyrethroid esters are prepared using a synthetic method from acids of the general formula IV: ##STR5## wherein R.sub.4 =lower alkyl having from 1 to 4 carbon atoms
R.sub.2 and R.sub.5 =H or lower alkyl PA0 R.sub.6 and R.sub.7 =Cl or Br PA0 R.sub.4 and R.sub.5 are independently H, a lower alkyl group having from 1 to 3 carbon atoms, polyhaloalkyl, haloalkyl, halogen, a lower alkenyl group having from 2 to 3 carbon atoms, a lower cycloalkyl group having from 3 to 5 carbon atoms, a lower cycloalkenyl group having from 3 to 5 carbon atoms, cyano, nitro, a lower alkoxy group having from 1 to 3 carbon atoms, arloxy, a lower alkylthio group having from 1 to 3 carbon atoms, arylthio, a lower alkylsulfinyl group having from 1 to 3 carbon atoms, arylsulfinyl, a lower alkylsulfonyl group having from 1 to 3 carbon atoms, arylsulfonyl, acylamido, or a lower dialkylamino group having from 1 to 3 carbon atoms; PA0 R.sub.6 is selected from the group consisting of: (1) cycloalkyl, alkenyl, branched alkenyl, or cycloalkenyl; or (2) a branched alkyl group having from 3 to 5 carbon atoms or an alkyl group having from 1 to 5 carbon atoms, with the proviso that R.sub.4 or R.sub.5 is other than hydrogen.